The mining newspaper for Alaska and Canada's North
The mining newspaper for Alaska and Canada's North
Critical Minerals Alliances 2024 - September 16, 2024
A silver metal with a melting temperature of 85.6 degrees Fahrenheit, gallium is a critical mineral that is increasingly being used in a wide array of high-tech, green energy, and military applications.
Electronic devices with gallium nitride transistors can be used in nuclear sensing equipment due to their high resistance to radiation.
Gallium is a technology metal with a melting point of 85.6 F.
Oak Ridge National Lab researcher Kyle Reed testing a gallium nitride transistor in the reactor pool at The Ohio State University Nuclear Reactor laboratory.
Sampling at Sheep Creek returned high-grade gallium, rare earths and other minerals critical to the U.S.
With a growing range of unique properties that are being leveraged in next-generation smartphones, shape-shifting robots, and catalysts that scrub carbon dioxide from the atmosphere, gallium is an uncanny tech metal that teeters on the edge of science fiction and science fact.
Gallium's unusual properties begin with its 85.6-degree Fahrenheit melting point, which means it is a solid at normal room temperatures but will melt into a pool of silvery liquid metal in the palm of your hand. While this mirror-like pool of metal is reminiscent of mercury, gallium is not toxic and is much safer to handle.
While gallium's low melting point, coupled with its ability to readily alloy with most metals, offers some intriguing possibilities for the future, the most popular current use for this metal is in semiconductors for high-tech applications.
"The development of gallium arsenide as a direct band-gap semiconductor in the 1960s led to what are now some of the most well-known uses of gallium – in feature-rich, application-intensive, third- and fourth-generation smartphones and in data-centric networks," the U.S. Geological Survey penned in a report on minerals and metals considered critical to the United States.
Electronic devices with gallium nitride transistors can be used in nuclear sensing equipment due to their high resistance to radiation.
Gallium arsenide and gallium nitride, which is a wide bandgap semiconductor, are used in next-generation smartphones, telecommunication networks, light-emitting diodes (LEDs), thin-film solar cells, quantum dots, and medical devices.
The high-tech liquid metal also demonstrates a surprising ability to greatly enhance the properties of other metals it is alloyed with, which is being leveraged by scientists to create self-cleaning "super catalysts" capable of scrubbing carbon dioxide out of the atmosphere and from industrial emissions.
Despite gallium's importance to today's and future technologies, the United States is reliant on imports for 100% of its supply of this avant-garde tech metal. Most of these supplies come from China, which produced roughly 98% of the world's gallium in 2023.
About a year ago, China put in place state-controlled restrictions on its exports of gallium, raising serious government and industry concerns about the impacts a shortage of gallium could have on America's high-tech and automotive sectors.
"Owing to China's 2023 gallium export controls, the United States and other countries began considering the start or restart of domestic primary gallium production," USGS penned in its 2024 Mineral Commodity Summaries report.
Roughly 74% of the gallium imported into the U.S. during 2023 was used in integrated circuits by the high-tech, automotive, aerospace, healthcare, telecommunications, and other sectors of the economy, according to the USGS. At around 25%, most of the rest of this tech metal went into optoelectronic devices such as laser diodes, LEDs, photodetectors, and solar cells.
While gallium arsenide is the older and more popular semiconductor compound made from this critical metal, gallium nitride offers some superior properties that make it increasingly important for the integrated circuits going into faster and more reliable telecommunications devices, servers, laptop adapters, and even onboard chargers for electric vehicles.
Gallium nitride semiconductors boast superior power density and heat resistance, which has traditionally been used primarily for military applications. Today, this semiconductor is finding more uses in 5G networks, commercial wireless infrastructure, power electronics, satellites, EVs, and consumer electronics.
"GaN offers higher power density, more reliable operation and improved efficiency over traditional silicon-only based solutions," Texas Instruments wrote about its portfolio of integrated circuits using gallium nitride power transistor technology.
In a quest to build more durable monitoring equipment for conventional nuclear reactors and next-generation microreactors, scientists at Oak Ridge National Laboratory have been testing the limits of gallium nitride's resistance to heat and radiation.
Oak Ridge National Lab researcher Kyle Reed testing a gallium nitride transistor in the reactor pool at The Ohio State University Nuclear Reactor laboratory.
To accomplish this, ORNL researchers placed gallium nitride transistors next to a research reactor core at Ohio State University. These transistors withstood high heat and radiation for three consecutive days, including seven hours, with the reactor running at 90% power.
The gallium nitride transistors stood up to 100 times higher accumulated dose of radiation than standard silicon devices at a sustained temperature of 125 degrees Celsius (257 degrees Fahrenheit) – far exceeding the team's expectations.
"We fully expected to kill the transistors on the third day, and they survived," said lead researcher Kyle Reed, a member of the Sensors and Electronics group at ORNL.
He hopes the ORNL research into gallium nitride for nuclear reactor electronics and other applications will create new markets for this wide bandgap semiconductor.
"We're opening up different side avenues for using gallium nitride, so we can start to create a more reasonable market demand for investment, research, and workforce development for subclasses of electronics beyond consumer-grade," Reed said.
While gallium's superior semiconductor properties keep this metal at the very vanguard of technological innovation, its ability to take on the catalytic properties of other metals it is alloyed with to create liquid metal "super catalysts" is pushing the bounds of science.
Gallium is a technology metal with a melting point of 85.6 F.
Though this research is still in its infancy, early results by Australian scientists seem to indicate that the properties of traditional catalysts such as platinum or nickel are multiplied many times over when suspended in liquid gallium.
Gallium-enhanced catalysts could be used to scrub CO2 from industrial emissions or the atmosphere, as well as improve industrial catalytic processes that are responsible for a significant portion of global greenhouse gas emissions.
In 2021, a team of Australian and U.S. researchers led by Professor Kourosh Kalantar-Zadeh at the University of New South Wales School of Chemical Engineering mixed nano-sized silver rods into gallium to create a catalyst able to break atmospheric CO2 down to its constituent parts – oxygen and carbon.
This process could be used to greatly reduce CO2 emissions from vehicles and industrial sites.
"We are very hopeful that this technology will emerge as the cornerstone of processes that will be internationally employed for mitigating the impact of greenhouse emissions," Kalantar-Zadeh said at the time.
In a paper detailing this technology, the researchers estimated it would cost about $100 per metric ton to convert CO2 into oxygen and a saleable carbon flake product that could be used in batteries or carbon fiber materials for high-performance products like aircraft, racing cars, and luxury vehicles.
The Australian research team created yet another liquid-metal catalyst in 2022 that is thousands of times better at scrubbing CO2 from industrial exhaust than solid-state platinum.
"To keep the single atoms separated from each other, the conventional systems require solid matrices to stabilize them. I thought, why not use a liquid matrix instead and see what happens," said Arifur Rahim, a postdoctoral research fellow at the University of New South Wales.
This pondering led to the discovery of a process to create a metal that enjoyed the liquidity of gallium and the catalytic properties of platinum.
Even more remarkably, at a ratio of less than 0.0001 parts platinum to one part gallium, this new liquid metal alloy is 1,000 times more efficient than a solid-state catalyst with around 10% platinum.
The liquidity of the gallium-platinum alloy offers yet one more advantage – it is self-cleaning.
Like a water fountain, the liquid mechanism constantly refreshes itself, self-regulating its effectiveness over time and avoiding the catalytic equivalent of pond scum building up on the surface.
As it turns out, platinum lends its catalytic abilities to gallium, a driving force behind the reaction.
"The platinum is actually a little bit below the surface and it's activating the gallium atoms around it," said Andrew Christofferson, an Exciton Science associate investigator who worked on the project. "So, the magic is happening on the gallium under the influence of the platinum. But without the platinum there, it doesn't happen."
In 2023, the Australian scientists came up with yet another gallium-based catalyst, this time for the chemical manufacturing side of the equation.
While the chemical sector and the catalysts that support it are largely unseen, they are an essential part of modern life. Paper, plastic, fertilizers, rubber, fuels, and laundry detergent are just a small sampling of the products that depend on the catalytic process.
While much of the global focus on reducing CO2 going into the atmosphere has been on obvious emitters such as vehicles and the generation of electricity, the production of chemicals accounts for nearly 15% of global CO2 emissions and climbing.
"It's expected that the chemical sector will account for more than 20% of emissions by 2050," said Kalantar-Zadeh. "But chemical manufacturing is much less visible than other sectors – a paradigm shift is vital."
Working on the same principles as the silver rod and platinum catalysts, the liquid gallium-nickel catalyst developed by Kalantar-Zadeh's team could substantially lower the energy required for chemical processes and, thus, the CO2 emitted by them.
"By dissolving nickel in liquid gallium, we gained access to liquid nickel at very low temperatures – acting as a 'super' catalyst," said Junma Tang, a postdoctoral researcher at the University of New South Wales.
The researchers said their formula could also be used for other chemical reactions by mixing metals using low-temperature processes.
"It requires such low temperature to catalyze that we could even theoretically do it in the kitchen with the gas cooktop – but don't try that at home," Tang said.
With China's hand on the gallium spigot, American tech manufacturers and the Pentagon are looking for alternative sources of this future-leaning tech metal.
Following China's 2023 announcement that all exports of this tech metal would require government authorization, a Pentagon spokesperson said, "The (Defense) Department is proactively taking steps using Defense Production Act Title III authorities to increase domestic mining and processing of critical materials for the microelectronics and space supply chain, including gallium and germanium."
Like many other critical minerals and metals, gallium is typically recovered as a byproduct of mining more common metals – primarily aluminum, zinc, and sometimes copper.
A recent report by the USGS, however, indicates that potential for domestic gallium production as a byproduct of base metal refining is low.
US Critical Materials Corp.'s Sheep Creek project in southwestern Montana, however, may host high enough concentrations of gallium, alongside high-grade rare earth elements and other critical minerals, that it could offer a domestic tech metals source that does not rely on other metals.
Sampling at Sheep Creek returned high-grade gallium, rare earths and other minerals critical to the U.S.
Analysis completed at Idaho National Lab earlier this year highlights Sheep Creek's potential as an extraordinarily high-grade domestic source of both rare earths and gallium.
Highlights from the samples analyzed by Idaho National Lab include:
• 13.45% total rare earth elements (TREE) and approximately 250 parts per million gallium.
• 13.82% TREE and approximately 300 ppm gallium.
• 17.78% TREE and approximately 350 ppm gallium.
"The gallium and rare earth grades, calculated and verified by Idaho National Laboratory, are higher than any that we are aware of in the United States," said US Critical Materials President Jim Hedrick.
Idaho National Lab is also developing a process to efficiently and sustainably recover and separate the rare earths, gallium, and other critical minerals found at Sheep Creek.
"Not only is our gallium high grade, but we are also confident that working together with Idaho National Laboratory, we will be able to create a proprietary separation process that will be environmentally respectful," said Hedrick.
Sheep Creek, however, is an early staged project that requires more exploration before it is ready for permitting and development into a potential future source of domestic gallium.
In the meantime, the USGS reports that "One company in New York recovered and refined high-purity gallium from imported primary low-purity gallium metal and new scrap" during 2023.
Over his more than 16 years of covering mining and mineral exploration, Shane has become renowned for his ability to report on the sector in a way that is technically sound enough to inform industry insiders while being easy to understand by a wider audience.
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